An Internal Gear may be described as the contrary of an external equipment in that the teeth point towards instead of away from the guts, and addendum and dedendum take reverse positions. Internal Gears give a compact parallel shaft tranny drive with large acceleration reduction. Used with a standard spur pinion the ratio is the same as that of two exterior gears, but the 
center distance is much smaller. In cases where it’s important to possess two parallel shafts rotate in the same direction, the inner gear eliminates the usage of an idler gear.
Internal Gears possess many advantages when properly applied. One such advantage is reduced sliding action. The corresponding working surfaces of the teeth of an internal gear and pinion are more nearly of the same size than may be the case with an external gear and pinion having the same tooth ratio and tooth size. Which means relative slippage of the teeth is less regarding the internal. This point presents among the advantages of using Internal Gears. The sliding action of 1 tooth over another causes friction; and since friction outcomes in tooth wear, a reduction in the amount of sliding action is desirable.
Internal Gear drives may be operated with the gear in a set position and the pinion planetary gearbox rotating along the pitch line, or the gear may be free to rotate with the pinion rotating in a fixed position.
When mating pinions are as well close in proportions to the gear, interference may result. Therefore, the difference in teeth of the pinion to the apparatus should not be less than 15.
RUSH GEARS inc. offers regular Internal Gears in Metal, STAINLESS STEEL, CAST IRON, BRONZE, ALUMINUM, DELRIN and NON-METALLIC (PHENOLIC). We will gladly manufacture made to order Internal Gears to your requirements.